In mammals, most lingual taste buds are contained in the epithelium of the clefts of the circumvallate and foliate papillae on the posterior tongue. Draining into the clefts via numerous ducts are secretions of the large, lingual salivary glands of von Ebner. The salivary secretions provide the microenvironment in which initial taste stimulus-receptor contact and subsequent transduction occur. We hypothesize that there is an interaction between the secretion of von Ebner's glands and taste receptor function, and propose a series of experiments in rats to begin to study the neural control of the glands and their association with gustatory sensation. (1) To clarify the extent to which the sympathetic nervous system controls gland secretion, the effects of various sympathetomimetic drugs on secretion will be quantified. (2) Neural recordings will be made from secretomotor cells in the brainstem which supply von Ebner's glands, during chemical stimulation of the posterior tongue with taste stimuli. We hypothesize that neural activity in the secretomotor cells will be altered during chemical stimulation of taste buds. (3) Neural recordings will be made from the glossopharyngeal nerve during chemical stimulation of the circumvallate papilla with taste stimuli. Then the contralateral glossopharyngeal nerve or the cervical sympathetic trunk will be stimulated to cause secretion from von Ebner's glands. We hypothesize that salivary secretion elicited by autonomic nervous system stimulation will affect peripheral nerve taste responses. These three objectives will begin to define the neural control of the glands, the effect of taste sensation on motor output to the glands, and the effect of gland secretion on taste responses. The experiments will lead to understanding the broad role of taste in ingestive and digestive functions, and the role of salivary secretions in taste function.